Stable mixed emulsions

Abstract

Stable mixed emulsion systems containing at least two discrete and distinctly different dispersed particle size ranges, i.e., both nanoemulsion and macroemulsion semisolid dispersions, as well as a method of making the same, are disclosed. The stable mixed emulsions may be used for cosmetic and dermatological applications and provide unique benefits.

1 . A stable mixed emulsion comprising semisolid dispersions of at least two discrete and distinctly different particle size ranges.  
     
     
         2 . The stable mixed emulsion of  claim 1 , wherein the semisolid dispersions comprise nanoemulsion semisolid dispersions having a particle size range of less than 1 μm and macroemulsion semisolid dispersions having a particle size range of greater than 1 μm.  
     
     
         3 . The stable mixed emulsion of  claim 2 , wherein the nanoemulsion semisolid dispersions have a particle size ranging from 10 nm to 900 nm.  
     
     
         4 . The stable mixed emulsion of  claim 2 , wherein the macroemulsion semisolid dispersions have a particle size ranging from 1 μm to 300 μm.  
     
     
         5 . The stable mixed emulsion of  claim 2 , wherein a weight ratio of nanoemulsion semisolid dispersions to macroemulsion semisolid dispersions ranges from 20:1 to 1:20.  
     
     
         6 . The stable mixed emulsion of  claim 1  further comprising a continuous phase, said continuous phase comprising water and a hydrocolloid.  
     
     
         7 . The stable mixed emulsion of  claim 6 , wherein the hydrocolloid is a polyacrylate.  
     
     
         8 . The stable mixed emulsion of  claim 6 , wherein the hydrocolloid is present in an amount ranging from 0.01% to 2% by weight of the stable mixed emulsion.  
     
     
         9 . The stable mixed emulsion of  claim 6 , wherein the water is present in an amount ranging from 20% to 99.9% by weight of the stable mixed emulsion.  
     
     
         10 . The stable mixed emulsion of  claim 2 , wherein the nanoemulsion semisolid dispersions comprise at least two nonionic emulsifiers and at least one lipophilic ingredient.  
     
     
         11 . The stable mixed emulsion of  claim 10 , wherein at least one of the at least two emulsifiers has an HLB of 8 or more and at least one of the at least two emulsifiers has an HLB below 8.  
     
     
         12 . The stable mixed emulsion of  claim 10 , wherein a weight ratio of lipophilic ingredient to emulsifier in the nanoemulsion semisolid dispersions ranges from 1:1 to 20:1.  
     
     
         13 . The stable mixed emulsion of  claim 2 , wherein the macroemulsion semisolid dispersions comprise at least one nonionic emulsifier and at least one lipophilic ingredient.  
     
     
         14 . The stable mixed emulsion of  claim 13 , wherein the at least one emulsifier has an HLB ranging from 8 to 18.  
     
     
         15 . The stable mixed emulsion of  claim 13 , wherein a weight ratio of lipophilic ingredient to emulsifier in the macroemulsion semisolid dispersions ranges from 20:1 to 1:3.  
     
     
         16 . The stable mixed emulsion of  claim 10  or  claim 13 , wherein the at least one lipophilic ingredient is selected from the group consisting of aliphatic hydrocarbons, natural oils, squalene, esters, branched chained esters, volatile hydrocarbons, waxes, silicones, active ingredients and combinations thereof.  
     
     
         17 . The stable mixed emulsion of  claim 1 , wherein the stable mixed emulsion is stable for at least a period of three years at 22° C.  
     
     
         18 . A skin care composition comprising the stable mixed emulsion of  claim 1 .  
     
     
         19 . The skin care composition of  claim 18  further comprising ingredients selected from the group consisting of humectants, preservatives, fragrance, color, natural extracts, and combinations thereof.  
     
     
         20 . A method of making a stable mixed emulsion comprising the steps of: 
 providing a nanoemulsion;    hydrating a hydrocolloid in a separate vessel;    adding the nanoemulsion to the hydrated hydrocolloid;    mixing macroemulsion oil phase ingredients in another separate vessel to form macroemulsion semisolid dispersions;    adding the macroemulsion semisolid dispersions to the hydrated hydrocolloid and the nanoemulsion; and    mixing until uniform to prepare the stable mixed emulsion.    
     
     
         21 . The method of making a stable mixed emulsion according to  claim 20 , wherein the step of preparing the nanoemulsion comprises a phase inversion temperature method.  
     
     
         22 . The method of making a stable mixed emulsion according to  claim 20 , wherein the weight ratio of nanoemulsion semisolid dispersions to macroemulsion semisolid dispersions ranges from 20:1 to 1:20.  
     
     
         23 . The method of making a stable mixed emulsion according to  claim 20 , wherein the ratio of a lipophilic ingredient to emulsifier in the nanoemulsion semisolid dispersions ranges from 1:1 to 20:1.  
     
     
         24 . The method of making a stable mixed emulsion according to  claim 20 , wherein the particle size of the nanoemulsion semisolid dispersions is less than 1 μm.  
     
     
         25 . The method of making a stable mixed emulsion according to  claim 24 , wherein the particle size of the nanoemulsion semisolid dispersions ranges from 10 nm to 900 nm.  
     
     
         26 . The method of making a stable mixed emulsion according to  claim 20 , wherein the ratio of a lipophilic material to emulsifier in the macroemulsion semisolid dispersions ranges from 20:1 to 1:3.  
     
     
         27 . The method of making a stable mixed emulsion according to  claim 20 , wherein the particle size of the macroemulsion semisolid dispersions is greater than 1 μm.  
     
     
         28 . The method of making a stable mixed emulsion according to  claim 27 , wherein the particle size of the macroemulsion semisolid dispersions ranges from 1 μm to 300 μm.